tough binomial function question!! help!!Watch
Then set x=1 in both the expansion and the original expression.
Choosing appropriate values for makes the answer fall out immediately.
© Copyright The Student Room 2017 all rights reserved
The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.
Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE